Findtheindicatedprobability.Roundtofourdecimalplaces.

1. Acarinsurancecompany hasdeterminedthat9%ofalldriverswereinvolvedinacaraccident lastyear.Amongthe10driverslivingononeparticularstreet,3wereinvolvedinacaraccidentlastyear.If10driversarerandomly selected,whatistheprobabilityofgetting3ormorewhowereinvolvedinacaraccidentlastyear?
2. Constructaprobabilityhistogram forthebinomialrandomvariable X. Threecoinsaretossed.Xisthenumberoftails.
3. Findthemeanofthebinomial randomvariable.Roundtotwodecimalplaceswhennecessary. Accordingtoacollegesurvey,22%ofallstudents workfulltime.Findthemeanfortherandom variableX,thenumberofstudentswhoworkfulltimeinsamplesofsize16.
4. Onamultiplechoicetestwith6questions,eachquestionhasfourpossibleanswers,oneofwhichiscorrect. Forstudentswhoguessatallanswers, findthemeanfortherandomvariable X,thenumberofcorrectanswers.
5. Findtheconfidenceinterval specified. 30studentswererandomlyselected fromalargegroupofstudentstakingacertain calculustest.Themeanscoreforthestudentsinthesamplewas78.Assumethata=14.5.Constructa99%confidence intervalforthemeanscore,,ofallstudents takingthetest.
6. Marywishestoestimatethemeanheightofwomenaged18-24.Shepicksasampleof100womenaged between18and24andconstructsa 99%confidenceintervalforthepopulationmean.Ifsheweretorepeatthisprocedure200timesintotal,shewouldobtain200different confidenceintervals.Howmanyoftheseintervals wouldyouexpecttocontain thepopulationmean,?Explainyourthinking.
7. Supposethatyouwishtoobtainaconfidenceinterval forapopulationmean.Undertheconditionsdescribedbelow,shouldyouusethez-intervalprocedure,thet-intervalprocedure, orneither?

• Thepopulationstandard deviationisunknown.
• Thedatacontainoutliers.
• Thesamplesizeissmall